Described herein are systems for capturing images and video of eyes, and methods associated with such systems.
A slit lamp is an instrument used by doctors (for example, ophthalmologists and optometrists) to examine a patient's eyes. A slit lamp includes a high-intensity light source that can be focused to shine a thin slit of light into an eye of the patient and a low-power microscope that magnifies an image of the eye being examined.
Conventional systems for capturing images or video of a patient's eye that are usable with slit lamps fall into one of two categories: video capture and image capture.
The first category is a video capture system that records video of the patient's eye using, for example, a digital video camera. There are several disadvantages to conventional video capture systems when used to capture still images. First, a flash cannot be used. This means high magnification shots are essentially impossible, as miniscule movements at high magnification produce substantial blur. Second, extremely high levels of light are required to get a good image, and such levels can be uncomfortable to the patient. Third, video capture systems typically capture low resolution video. One particular conventional video capture system markets an ability to capture images. In reality, however, this video capture system merely provides a user with a series of images surrounding an image capture time, and requires the user to select a particular image to use. This approach not only provides the user with multiple inferior images, but also increases the amount of time necessary to obtain an image of a particular region of the eye.
The second category is an image capture system that captures images of the patient's eye using, for example, a digital single lens reflex (SLR) camera. Conventional image capture systems have the capability to capture higher resolution and thus higher quality images than conventional video capture systems. Conventional image capture systems, however, can also have drawbacks. For example, certain conventional image capture systems cannot capture video. As another example, certain conventional image capture systems require all of the light to be directed to the digital SLR camera when the image capture system is in use. This leaves no light for the slit lamp microscope and renders it impossible for the user to examine the patient's eyes while using the image capture system. Another disadvantage is that conventional image capture systems require the user to manually adjust a variable aperture during photo taking sessions and to know proper ISO (e.g. ISO standard 12232:2006 which is a system used to measure the sensitivity of digital imaging systems), flash, and variable aperture settings for the extensive variations of eye regions and for varying levels of magnification. These requirements can cause the user to devote time to adjusting settings during a patient examination, and/or can distract the user from the examination.
References that discuss slit lamps and/or capturing video images of all or part of an eye are disclosed in U.S. Pat. No. 4,175,839 to Muller et al., U.S. Pat. No. 4,331,392 to Sato, U.S. Pat. No. 4,767,204 to Blaha, U.S. Pat. No. 5,000,560 to Papritz et al., U.S. Pat. No. 5,196,874 to Muller et al., U.S. Pat. No. 5,424,788 to Satake et al., U.S. Pat. No. 5,757,461 to Kasahara et al., U.S. Pat. No. 7,311,401 to Goldfain et al., and U.S. Pat. No. 7,410,257 to Takeda. These references are herein incorporated by reference in their entirety.